Clinical Study Of The Pulmonary Vein With DSCT

Objectives:1.To discuss the effects of two kinds of enhanced CT scan of pulmonary vine respectively using blous tracking and test-blous with dual source CT; 2.To find out the impact of individual factors such as heart rate, weight and CTR on the image quality of enhanced pulmonary vine CT scan; 3.To compare variation rate of pulmonary vein between AF and N-AF groups, and then to analyze the relationship between variation of pulmonary vein and AF;4. To assess the feasibility of enhanced pulmonary vine CT scan with low radiation dose using tube voltage of 100 kV combined with automatic mA regulation technology(Care Dose 4D).Materials and Methods:1.190 patients accepted DSCT enhanced chest scan in the First Affiliated Hospital of Kunming Medical College from 2008 to 2009 were divided into A and B group; 130 patients in group A were conducted blous tracking, while 60 subjects from group B were implemented in test-blous, then to use the quantitative evaluation method of pulmonary vein, pulmonary artery and pulmonary arteriovenous difference and 5-point qualitative evaluation method of image quality by the eye for estimating the image quality and contrasting the dosage of contrast agent and enhanced scan time; 2.To analyze the impact of heart rate, weight, CTR recorded according to patients in group A on enhanced pulmonary vine CT scan; 3.To compare the variation rate and types of pulmonary vein openings between 190 cases of non-AF (group C) and 11 cases of AF (group D);4.69. adult patients accepted DSCT enhanced chest scan in the First Affiliated Hospital of Kunming Medical College from 2009 to 2010 were randomly divided into two groups. 26 cases in group E were accepted enhanced pulmonary vine CT scan with tube voltage of 100 kV, while 43 cases in group F were with the standard tube voltage of 120 kV combined with the automatic mA regulation technology. To find out the differences in volume computed tomography dose index (CTDI), dose length product (DLP) and effective dose (ED) and to calculate signal-noise-ratio (SNR) and contrast-to-noise-ratio (CNR) by measurement of enhanced CT value of pulmonary vein and back noise. Then evaluate the image qualities of two groups according quantitative and qualitative analysis.Results:1.Group A:the average CT values of pulmonary vein, pulmonary artery and pulmonary arteriovenous difference were 159.77±70.70,344.11±99.38,189.16±86.20; Group B: the average CT values of pulmonary artery, pulmonary vein and pulmonary arteriovenous difference were 179.47±51.63,365.50±94.05,189.744±83.26; there was no significant difference in imaging quality between two kinds of enhanced pulmonary vine CT scan (compare two sets of data, pulmonary artery F=3.74, P> 0.05, pulmonary vein F=1.967, P> 0.05 and pulmonary arteriovenous difference F=0.020, P> 0.05).The scores of image quality of two groups were no significant differences (Z=-1.06, P> 0.05).The dosage of contrast agent were respectively 60 and 70ml in group A and group B, while the dosage of normal saline were 30 and 70ml. The enhanced scan time was 34.81±2.19s in group A and 97.10±1.68s in group B, so 62.29s was saved in group A (t'=-214.73,P＜0.001).2.In 130 cases of A group, there were no significant differences in the enhanced CT value of pulmonary artery, pulmonary vein, pulmonary arteriovenous difference and the grade scale based on different heart rates (P> 0.05);there were significant difference in the enhanced CT value of pulmonary artery and vein for different body weight (P<0.05) and no difference in pulmonary arteriovenous difference (P> 0.05), the greater the weight, the lower the enhanced pulmonary artery and vine CT value; there were significant differences in enhanced CT value of pulmonary artery, pulmonary vein and pulmonary arteriovenous difference based on different CRT (P< 0.05), the larger CTR, the higher the enhanced CT value of pulmonary artery, the lower the enhanced pulmonary vine CT value (B=-19.18) and the smaller the pulmonary arteriovenous difference.3.142 cases (74.7%) had four pulmonary veins of Non-AF (group C); variation 48 cases, of which 10 cases(5.3%)had three veins(common ostia of left pulmonary vein), 31cases(16.3%)had five veins,5cases(2.6%)had six anomalies and 2cases(1.0%)had seven anomalies.4.6 cases (54.55%)had four pulmonary veins and variation in 5 cases for group D, with the variation rate of 45.45%.In 5 variation patients,3cases(27.27%) had five veins, of which the middle lobe pulmonary vein drained directly into the left atrium in 2 patients, right inferior drained directly in one case,2cases(18.18%) had six, which is the middle lobe pulmonary vein and the right inferior drained directly into the left atrium.There was no significant difference in the variation rate of pulmonary vine between two groups (P>0.05).5.DLP and ED were respectively (92.62±33.31) mGy·cm and(1.30±0.47)) mSv VS in group E, while(122.79±35.07)mGy·cm and(1.72±0.49)mSv in group F. The difference had statistic significance(P＜0.001)which shown the radiation dose was different between two groups and ED,DLP in group E was reduced 24% than group F. Quantitative evaluation of image quality:SNR were respectively 36.78±11.63 and 36.26±10.08 for group E and F and the difference had no statistic significance (P=0.89); CNR were respectively 32.79±10.86 and 32.14±9.31 for each group and the difference also had no statistic significance (P=0.86); the scores of image quality estimated by the eye were 5 score in 12 cases,4 score in 10case and 3 score in 2 cases for group E and 5 score in 31 cases,4 score in 8 cases and 3 score in 4 cases for group F; the difference had no statistic significance (P=0.13).Conclusion:1.Bolus tracking and test bolus can be used for enhanced CT scan of pulmonary vine and both of them had no different imaging effect, can showed more than three to six high-quality images of pulmonary vein clearly, and the success rate of 98.5%.But the latter one need more contract agent, saline and scan time.2.The imaging effect of enhanced CT scan of pulmonary vine was influenced by individual factors such as weight and CNR but heart rate had no effect on imaging effect.3.The number of pulmonary veins was variant in non-AF and AF group, in which the single opening of right pulmonary vein in the middle lobe and three vines to left atrium had highest variation rate; but there was no statistic difference between non-AF and AF groups.4. The enhanced DSCT scan of pulmonary vine with tube voltage of 100 kV and 120kv combined with automatic mA regulation technology can reduce the radiation dose in 26% without sacrificing the image quality.